Search Engine Land recently launched Sphinn a social site for search & internet marketing professionals. From their description;
"It's designed to allow you to share and discover news stories, read and take part in discussions, discover events of interest and network with others."
The interface might look familiar to those who use Digg. Stories are posted by the Search Engine Land staff as well users and anyone can Digg It or in this case Sphinn it! The site has all the usual social networking tools. If you're in this field it's worth a look